Wireless communications systems are used in a variety of telecommunications systems, television, radio and other media systems, data communication networks, and other systems to convey information between remote points using wireless transmitters and wireless receivers. A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. Transmitters often include signal amplifiers which receive a radio-frequency or other signal, amplify the signal by a predetermined gain, and communicate the amplified signal. On the other hand, a receiver is an electronic device which, also usually with the aid of an antenna, receives and processes a wireless electromagnetic signal. In certain instances, a transmitter and receiver may be combined into a single device called a transceiver.
Certain components of a transmitter or receiver (e.g., power amplifiers and/or automatic gain control circuits of variable gain amplifiers) may employ electronic switches. Generally speaking, an ideal switch is an electrical component that may selectively open an electrical circuit (e.g., turning the switch “off,” thereby interrupting current in the circuit) or close the electrical circuit (e.g., turning the switch “on,” thereby providing a path for current in the circuit). In practical applications, and particularly at high frequencies and radio frequencies, switches do not typically act in an ideal manner, and may conduct a small amount of current even when off, a phenomenon known as leakage. While an amount of current due to leakage may be small enough to be ignored in some applications, in other applications (e.g., radio-frequency applications) the leakage current may be large enough that it may lead to undesirable effects in a circuit unless compensated, corrected, or cancelled.